BUSINESS INFORMATION SYSTEM BUSINES ECONOMICS I
BIS 1, 2 Intro + Basics:
Contact: acthys@vub.ac.be
02/614 83 37
Room PL 5.4.26
Friday 16-20 room B001
Final grade: 50% theoretical, 50% practical
Introduction:
- General competences:
o Recognize business information systems and analyze their impact
o Understanding the collaboration between hardware, software and network
o Being able to name common abbreviations and terminology
o Being able to distinguish the historical context and trends in IT
o Creating simple data analysis algorithms
Basic concepts:
- A few facts:
o Information technology has become very important nowadays, but many projects fail
because of:
§ Shortages or even absence of agreements,
§ Wrong explanation or misrepresentation
§ …
o IT is very important for a company, an organization and its management team for:
§ Good communication
§ Efficiency
§ …
§ Ex.: tax-on-web, Amazon, Bol.com (fast, tracking, ordering…)
o High investments in IT do not always mean a higher productivity:
o 80-90% of all the IT projects fails!!
o Business >< IT alignment:
§ Business:
• Cost
• Benefits
• Timing
• Strategy
• Functional
• Requirement
• …
§ IT:
• Design
• Technology
• Programming
• Technical Constraints
• …
o When we have problems with the IT then you have problems with:
§ Web-shop
§ Management of orders
§ Payments
§ Customer service
§ …
§
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- Some concepts:
o Hardware:
§ The collection of physical parts of a computer system
§ All the parts you can physically touch
§ Increasingly resent in our modern society
§ Some example: computer case, keyboard, monitor
§ A laptop and a desktop computer have the same hardware componence
even though they look very different
o Software:
§ Something you CAN NOT touch
§ A set of instructions for a computer to perform specific operations
§ The part which activates the physical component, it includes the features
that responsible for directing the work to the hardware
§ Software can be divided into other programs and date
§ Conversion into machine language
• Machine language:
o The set of symbolic instruction codes usually in binary form
that is used to represent operations and data in a machine.
§ Modules:
• Reuse ?!
• Less complex
• Splitting into sub-problems
• Error module easier to find
• Collaboration with several people
à you need both for a computer system to work!!
o Database:
§ Organized collection of data stored in a computer
§ Relational database
o Network:
§ Multiple computers to communicate and exchange data
§ Types: PAN, LAN, MAN, WAN
§ Protocols TCP, IP
o Servers:
§ Computer only calculation and storage (no screen, no keyboard)
§ Ex.: mail server, web server…
o Internet :
§ The biggest internetwork
§ In OECD penetration rate of +- 83%
o Computer architecture:
§ Fundamental organization of the computer system
• Phase 1: mainframe
• Phase 2: PC & client server
• Phase 3: Browser/ cloud
o Processes:
§ A business process is a sequence of steps/ actions with the aim of generating
a product or a service.
§ Start in 90’: need for operation between the various actors/ departments
within an organization
o Information System:
§ The combination of IT hardware, software, processes and people who use it
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BIS3: Algorithms:
The central theme of computer science is the study of algorithms
The role of Algorithms:
- An algorithm:
o A set of steps that defines how a track is performed
o Ex. algorithms for cooking à recipes, for finding your way à directions, for playing
music à sheet music…
o Before a machine such as a computer can perform a task, an algorithm for
performing that task must be discovered and represented in a form that is
compatible with the machine.
o Representation of an algorithm
§ A program
• They are of developing a program, encoding it in machine-
compatible from, and inserting it into a machine à programming
o Programs, and the algorithms they represent, are collectively referred to as software,
in contrast to the machinery itself, which is known as hardware.
- The goal:
o To find a single set of directions that described how all problems of a particular type
could be solved
o Ex. : Euclidean algorithm à discovered by the ancient Greek mathematician Euclid,
for finding the greatest common divisor of 2 positive integers
- Once an algorithm for performing a task has been found, the performance of that task no
longer requires an understanding of the principles on which the algorithm is based. Instead,
the performance of the task is reduced o the process or merely following directions
- An algorithm for a magic trick:
o Effect: the performer places some cards from a normal deck of playing cards face
down on a table and mixed them thoroughly while spreading them out on the table.
Then, as the audience requests either red or black cards, the performer turns over
cards of the requested color.
o Secret and patter:
§ Step 1: From a normal deck of cards, select ten red and ten black cards. Deal
these cards face up in 2 piles on the table according to color
§ Step 2: Announce that you have selected some red cards and some black
cards
§ Step 3: Pick up the red cards. Under the pretense of aligning them into a
small deck, hold them face down in your left hand and, with the thumb and
first finger of your right hand, pull back on each end of the deck so that each
card is given a slightly backwards curve. Then place the deck of red cards face
down on the table as you say, “here are the red cards in this stack”
§ Step 4: Pick up the black cards. In a manner similar to that in step 3, give
these cards a slight forward curve. Then return these cards to the table in a
face-down deck as you say, “and here are the black cards in this stack.”
§ Step 5: immediately after returning the black cards to the table, use both
hands to mix the red and black cards (still face down) as you spread them out
on the tabletop. Explain that you are thoroughly mixing the cards.
§ Step 6: As long as there are face-down cards on the table, repeatedly execute
the following steps:
• 6.1: Ask the audience to request either a red or a black card.
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• 6.2: If the color requested is red and there is a face-down card with a
concave appearance, turn over such a card while saying, “here is a
red card.”
• 6.3: if the color requested is black and there is a face-down card with
a convex appearance, turn over such a card while saying, “here is a
black card.”
• 6.4: otherwise, state that there are no more cards of the requested
color and turn over the remaining cards to prove your claim.
- Capturing and conveying intelligence (or at least intelligent behavior) by means of algorithms
allows us to build machines that perform useful tasks.
- The level of intelligence displayed by machines is limited by machine to perform a task only If
an algorithm exists for performing that task. SO if no algorithm exists for solving a problem,
then the solution of that problem lies beyond the capabilities of machines
(Chapter 5 in book p217)
The concept of an Algorithm:
- An informal review:
o There are a multitude of algorithms in our study:
§ Converting numeric representation from one form to another
§ Detecting and correcting errors in data
§ Compressing and decompressing data files
§ Controlling multiprogramming in a multitasking environment
§ …
o As long as the halt instruction had not been executed continue to execute the
following steps:
§ Fetch an instruction
§ Decode the instruction
§ Execute the instruction
o Algorithms are not restricted to technical activities, they even underlie even such
mundane activities as shelling peas.
§ Obtain a basket of unshelled peas and an empty bowl. As long as there are
unshelled peas is the basket continue to execute the following steps:
• Take a pea from the basket
• Break open the pea pod
• Dump the peas from the pod into the bowl
• Discard the pod
o In fact, many researchers believe that every activity of the human mind, including
imagination, creativity and decision making, is actually the result of algorithm
execution
- The formal definition of an Algorithm:
o Informal, loosely defined concepts are acceptable and common in everyday life, but a
science must be based on well-defined terminology.
o An algorithm is an ordered set of unambiguous, executable steps that defines a
terminating process.
- The Abstract nature of Algorithms:
o It is important to emphasize the distinction between an algorithm and its
representation – a distinction that is analogous to that between a story and book:
§ A story = abstract or conceptual in nature
§ A book= physical representation of a story
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